Medical observation device and medical observation method

ABSTRACT

To suppress sudden changes in brightness due to a disturbance in a captured image, provided is a medical observation device, including: an acquisition section that acquires a sensing result of a brightness of an image of a subject in a living organism; and a control section that decides, according to a first interval in which the brightness sensing result indicates a value inside a certain range, a second interval in which to maintain an exposure of an imaging section at an exposure corresponding to a value included in the range.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/323,742, filed Jan. 4, 2017, which is the U.S. National Stageapplication of International Application No. PCT/JP2016/064125, filedMay 12, 2016, which claims priority to Japanese Application No.2015-139312, filed Jul. 1, 2015. U.S. application Ser. No. 15/323,742 isherein incorporated by reference in its entirety for all purposes.

TECHNICAL FIELD

The present disclosure relates to a medical observation device and amedical observation method.

BACKGROUND ART

Recently, due to advancements in surgical techniques and surgicalequipment, surgeries for performing various treatments (also calledmicrosurgery) while observing an affected site with an observationdevice for medical use, such as an endoscope or a surgical microscope,are coming to be conducted frequently. Also, such observation devicesfor medical use are not limited to devices that enable opticalobservation of the affected area, and also include devices that displayan image of the affected area captured by an imaging section (camera) orthe like as an electronic image on a display such as a monitor. Forexample, Patent Literature 1 discloses an example of a technology thatcaptures an observation image from an endoscope with an imaging section,and displays the captured observation image as an electronic image on adisplay.

CITATION LIST Patent Literature

-   Patent Literature 1: JP 2001-37711A

DISCLOSURE OF INVENTION Technical Problem

On the other hand, for example, under circumstances in which a medicalobservation device such as an endoscope or a surgical microscope isused, a case is conceivable in which objects such as forceps and gauzeare inserted into the observation range of the medical observationdevice (that is, inside the field of view of the imaging section). Inthis way, under circumstances in which a comparatively brighter objectthan the target of observation (in other words, a high-luminancesubject) enters into the field of view of the imaging section, in somecases the brightness in the field of view may be treated as havingbecome brighter, and an action such as controlling the shutter speedmore rapidly or decreasing the gain may be performed to control theexposure (amount of exposure) of the imaging section so that thecaptured image of the subject becomes darker, for example. Such casesmay sometimes reveal a phenomenon in which the brightness of the imagechanges suddenly, such as the output image of the target of observation(in other words, the image of the subject) becoming dark temporarily,for example. Such brightness changes in the image (particularly, theimage of the target of observation) due to an outside disturbance may beanticipated to obstruct the work of the surgeon performing a medicalprocedure while observing the image.

Accordingly, the present disclosure proposes a medical observationdevice and a medical observation method capable of suppressing suddenchanges in brightness due to a disturbance in a captured image.

Solution to Problem

According to the present disclosure, there is provided a medicalobservation device, including: an acquisition section that acquires asensing result of a brightness of an image of a subject in a livingorganism; and a control section that decides, according to a firstinterval in which the brightness sensing result indicates a value insidea certain range, a second interval in which to maintain an exposure ofan imaging section at an exposure corresponding to a value included inthe range.

According to the present disclosure, there is provided a medicalobservation method, executed by a processor, including: acquiring asensing result of a brightness of an image of a subject in a livingorganism; and deciding, according to a first interval in which thebrightness sensing result indicates a value inside a certain range, asecond interval in which to maintain an exposure of an imaging sectionat an exposure corresponding to a value included in the range.

Advantageous Effects of Invention

According to the present disclosure as described above, there isprovided a medical observation device and a medical observation methodcapable of suppressing sudden changes in brightness due to a disturbancein a captured image.

Note that the effects described above are not necessarily limitative.With or in the place of the above effects, there may be achieved any oneof the effects described in this specification or other effects that maybe grasped from this specification.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an explanatory diagram for explaining an example of aschematic configuration of a system applying a medical observationdevice according to an embodiment of the present disclosure.

FIG. 2 is an explanatory diagram for explaining an example of exposurecontrol.

FIG. 3 is a block diagram illustrating an example of a functionalconfiguration of a medical observation device according to theembodiment.

FIG. 4 is a flowchart illustrating an example of the flow of a series ofprocesses by a medical observation device according to the embodiment.

FIG. 5 is an explanatory diagram for explaining an example of exposurecontrol by a medical observation device according to the embodiment.

FIG. 6 is an explanatory diagram for explaining an example of exposurecontrol by a medical observation device according to a modification ofthe embodiment.

FIG. 7 is an explanatory diagram for explaining another example ofexposure control by a medical observation device according to amodification of the embodiment.

FIG. 8 is an explanatory diagram for explaining another example ofexposure control by a medical observation device according to amodification of the embodiment.

FIG. 9 is an explanatory diagram for explaining an application of amedical observation device according to the embodiment.

FIG. 10 is a function block diagram illustrating an exampleconfiguration of the hardware configuration of an information processingdevice configured as a medical observation device according to theembodiment.

MODE(S) FOR CARRYING OUT THE INVENTION

Hereinafter, (a) preferred embodiment(s) of the present disclosure willbe described in detail with reference to the appended drawings. In thisspecification and the appended drawings, structural elements that havesubstantially the same function and structure are denoted with the samereference numerals, and repeated explanation of these structuralelements is omitted.

Hereinafter, the description will proceed in the following order.

1. System configuration

2. Investigation regarding exposure control

3. Functional configuration

4. Processes

5. Modifications

6. Applications

7. Hardware configuration

8. Conclusion

1. System Configuration

First, an example of the configuration of a system applying a medicalobservation device according to the present embodiment will be describedwith reference to FIG. 1. FIG. 1 is an explanatory diagram forexplaining an example of a schematic configuration of a system applyinga medical observation device according to the present embodiment.

For example, FIG. 1 illustrates an example of an endoscopic surgicalsystem used in endoscopic surgeries of the abdomen, conducted as asubstitute for abdominal surgeries of the past in the medical field. Asillustrated in FIG. 1, in an endoscopic surgery of the abdomen, insteadof opening up the abdomen by cutting abdominal wall like in the past,hole-opening tools called trocars 25 a and 25 b are attached to theabdominal wall in several places, and tools such as a laparoscope(hereinafter also called an endoscope) 11, an energy treatment tool 22,and forceps 23 are inserted into the body through holes provided in thetrocars 25 a and 25 b. Subsequently, a treatment such as excising anaffected area U is conducted with the energy treatment tool 22 and thelike while viewing in real-time an image of the affected area (such as atumor) U video-captured by the endoscope 11. Note that the endoscope 11,the energy treatment tool 22, and the forceps 23 are held by a surgeon,an assistant, a scopist, or a robot or the like.

Inside the operating room where such an endoscopic surgery takes place,a cart 31 bearing devices for the endoscopic surgery, a patient bed 33on which the patient lies, a footswitch 35, and the like are disposed.Also, on the cart 31, devices such as a camera control unit (CCU) 13, alight source device 17, a treatment tool device 21, a pneumoperitoneumdevice 24, a display device 15, a recorder 26, and a printer 27 areplaced as medical equipment.

An image signal of the affected area U captured through an observationoptical system of the endoscope 11 is transmitted to the CCU 13 via acamera cable. Note that the CCU 13, besides being connected to theendoscope 11 via the camera cable, may also be connected to theendoscope 11 via a wireless communication link. The CCU 13 performssignal processing on the image signal output from the endoscope 11, andoutputs the processed image signal to the display device 15. Accordingto such a configuration, an endoscopic image of the affected area U isdisplayed on the display device 15.

Note that the CCU 13 may also output the processed image signal to therecorder 26, and thereby cause the recorder 26 to record the endoscopicimage of the affected area U as image data (for example, moving imagedata). Additionally, the CCU 13 may also output the processed imagesignal to the printer 27, and thereby cause the printer 27 to print outan endoscopic image of the affected area U.

The light source device 17 is connected to the endoscope 11 via a lightguide cable, and is able to radiate light onto the affected area U whileswitching among various wavelengths of light. Note that in some cases,the light radiated from the light source device 17 is also used asauxiliary light, for example.

The treatment tool device 21 corresponds to a high-frequency outputdevice that outputs a high-frequency current to the energy treatmenttool 22 that cuts the affected area U using electrical heat, forexample.

Additionally, the pneumoperitoneum device 24 is provided with blowingand suction means, and is for blowing air into the patient's bodycavity, such as the abdominal region, for example.

The footswitch 35 is configured to control the CCU 13, the treatmenttool device 21, or the like by using a foot operation by a person suchas the surgeon or an assistant as a trigger signal.

The above thus references FIG. 1 to describe an example of a schematicsystem configuration of what may be termed an endoscopic surgical system1 as a system configuration applying a medical observation deviceaccording to an embodiment of the present disclosure.

2. Investigation Regarding Exposure Control

Next, to more easily understand the features of a medical observationdevice according to an embodiment of the present disclosure, an overviewof exposure control in an imaging section included in the endoscope 11or the like will be described, followed by a summary of the challengesof a medical observation device according to the present embodiment.

The imaging section is sometimes configured so that exposure iscontrolled according to a sensing result of the brightness of a subjectimage or the brightness of a captured image of the subject (in otherwords, configured so that the brightness of the captured image of thesubject is controlled). Note that in the present description, for thesake of convenience, the primary agent that controls the exposure of theimaging section is described as being the CCU.

For example, the CCU senses (detects) the brightness of a subjectedcaptured in an image (image plane luminous intensity), based on an imagesignal captured by an image sensor such as a complementarymetal-oxide-semiconductor (CMOS) image sensor or a charge-coupled device(CCD) image sensor (for example, an image sensor provided in the imagingsection). Also, as another example, the CCU may also acquire a sensingresult of the brightness (illuminance) of a subject image from a sensingsection such as a photometric sensor provided in the imaging section.Note that in the following description, the detection result for thebrightness of a subject image or the brightness of a captured image of asubject may sometimes be designated simply the “detection value”.Subsequently, the CCU, based on the acquired detection value, controlsthe shutter speed of the imaging section or controls the gain applied tothe captured image signal (in other words, controls the exposure of theimaging section) so that the brightness of the image of the subjectcaptured by the imaging section (that is, the image plane luminousintensity) becomes a more preferable state (for example, to reach acorrect exposure). Note that in the following description, the term“gain”, unless specifically noted otherwise, refers to the gain appliedto a captured image signal.

For example, FIG. 2 is an explanatory diagram for explaining an exampleof exposure control. In FIG. 2, the reference sign L1 indicates thedetection value in the case in which the brightness of the capturedimage of the subject is correct (that is, the detection value at which acorrect exposure is reached). Note that in the following, the detectionvalue indicated by the reference sign L1 may sometimes be designated the“reference value”.

In contrast, the reference sign L2 indicates a detection value greaterthan the reference value L1. In other words, if the detection value L2is acquired, the brightness of the image of the subject is brighter thanthe case of a correct exposure. For this reason, in this case, the CCUcontrols the exposure of the imaging section to decrease the amount ofexposure. Specifically, the CCU controls the shutter speed of anelectronic shutter of the imaging section to be faster than the currentvalue, for example. Additionally, the CCU may also control the gain tobe lower than the current value. According to such control, the capturedimage of the subject is controlled to become darker, or in other words,the brightness of the image is controlled to approach the brightness ofan image corresponding to the reference value L1.

In addition, the reference sign L3 indicates a detection value smallerthan the reference value L1. In other words, if the detection value L3is acquired, the brightness of the image of the subject is darker thanthe case of a correct exposure. For this reason, in this case, the CCUcontrols the exposure of the imaging section to increase the amount ofexposure. Specifically, the CCU controls the shutter speed of anelectronic shutter of the imaging section to be slower than the currentvalue, for example. Additionally, the CCU may also control the gain tobe higher than the current value. According to such control, thecaptured image of the subject is controlled to become brighter, or inother words, the brightness of the image is controlled to approach thebrightness of an image corresponding to the reference value L1.

On the other hand, as discussed earlier with reference to FIG. 1, undercircumstances in which a medical observation device is used, such asduring an endoscopic surgery of abdomen, a case is conceivable in whichobjects different from the target of observation (test subject), such asforceps and gauze, are inserted into the observation range of themedical observation device (that is, inside the field of view of theimaging section). Particularly, under circumstances in which acomparatively brighter object than the target of observation (in otherwords, a high-luminance subject) enters into the field of view of theimaging section, in some cases the brightness in the field of view maybe treated as having become brighter, and an action of controlling theexposure of the imaging section (for example, controlling the shutterspeed more rapidly or decreasing the gain) may be performed so that thecaptured image of the subject becomes darker. Such cases may sometimesreveal a phenomenon in which the brightness of the image of the subjectchanges suddenly, such as the output image of the target of observation(for example, the image of the affected area inside the body) becomingdark temporarily, for example. Such brightness changes in the image(particularly, the image of the target of observation, such as theaffected area) due to an outside disturbance may be anticipated toobstruct the work of the surgeon performing a medical procedure whileobserving the image.

Accordingly, a medical observation device according to the presentembodiment provides a mechanism enabling the suppression of suddenchanges in the brightness of the captured image, even undercircumstances in which a disturbance occurs, such as a high-luminancesubject, like forceps or gauze, entering into the observation range.Note that in the following, a medical observation device according tothe present embodiment will be described in further detail.

3. Functional Configuration

First, FIG. 3 will be referenced to describe an example of a functionalconfiguration of a medical observation device according to the presentembodiment, with particular focus on operations related to the controlof the brightness of a captured image of a subject (in other words,exposure control). FIG. 3 is a block diagram illustrating an example ofa functional configuration of a medical observation device according tothe present embodiment, and illustrates an example of a functionalconfiguration with particular focus on a process of capturing an imageof a target of observation (test subject) and displaying the image.

As illustrated in FIG. 3, a medical observation device 100 according tothe present embodiment includes an imaging section 110 (for example, acamera head), a control section 130, and a display section 150. Notethat the medical observation device 100 illustrated in FIG. 3 may beconfigured as the endoscopic system 1 illustrated in FIG. 1, forexample. In other words, the imaging section 110, the control section130, and the display section 150 illustrated in FIG. 3 correspondrespectively to the endoscope 11, the CCU 13, and the display device 15in the endoscopic surgical system 1 illustrated in FIG. 1, for example.

The imaging section 110 corresponds to a configuration that captures animage such as a moving image or a still image, like what is commonlycalled a camera or the like, and includes an imaging optical system (forexample, a series of lens groups) 111, and an image sensor 113. Theimaging optical system 111 focuses an optical image of a subject on theimaging surface of the image sensor 113. For the image sensor 113, asensor such as a CMOS image sensor or a CCD image sensor may be applied,for example. The image sensor 113 converts the optical image focused onthe imaging surface into an electrical signal by photoelectricconversion. Note that the operation of the image sensor 113 at thispoint (for example, the shutter speed or gain) is controlled by thecontrol section 130 discussed later (in other words, exposure iscontrolled by the control section 130). Subsequently, the image sensor113 outputs the electrical signal generated by photoelectric conversionto the control section 130.

The control section 130 includes an imaging signal processing section131, an image processing section 133, and an exposure control section135.

The imaging signal processing section 131 generates an image signal byexecuting various processes on the electrical signal generated byphotoelectric conversion in the image sensor 113, such as a linearmatrix process, a white balance process, and a gamma correction process,for example. The image signal generated by the imaging signal processingsection 131 is input into the image processing section 133. The imageprocessing section 133 performs image processing on the acquired imagesignal depending on the intended purpose, such as various correctionprocesses like color correction and luminance correction, video signalgeneration, or an encoding process or the like, and outputs an imagebased on the result of the image processing to the display section 150,for example.

In addition, the imaging signal processing section 131 outputsinformation required for exposure control of the image sensor 113 to theexposure control section 135. More specifically, the imaging signalprocessing section 131 performs detection processing on the electricalsignal generated by photoelectric conversion in the image sensor 113,and outputs a result of the detection process (namely, a detectionvalue) to the exposure control section 135.

The exposure control section 135 acquires a detection value as a resultof the detection processing from the imaging signal processing section131, and based on the acquire detection value, controls the shutterspeed or the gain of the image sensor 113 (in other words, controls theexposure of the imaging section 110). For example, as discussed earlierwith reference to FIG. 2, if the acquired detection value is divergentfrom a reference value, the exposure control section 135 may treat thereference value as a target value, and control the exposure of theimaging section 110 so that the acquired detection value approaches thetarget value.

As a more specific example, if the brightness of the image of thesubject based on the detection value is recognized to be brighter thanthe case of a correct exposure corresponding to the reference value, theexposure control section 135 controls the exposure of the imagingsection 110 so that the amount of exposure becomes smaller. In thiscase, for example, the exposure control section 135 controls the shutterspeed of an electronic shutter in the image sensor 113 more rapidly, orcontrols the gain to be lower.

Also, as another example, if the brightness of the image of the subjectbased on the detection value is recognized to be darker than the case ofa correct exposure corresponding to the reference value, the exposurecontrol section 135 controls the exposure of the imaging section 110 sothat the amount of exposure becomes larger. In this case, for example,the exposure control section 135 controls the shutter speed of anelectronic shutter in the image sensor 113 more slowly, or controls thegain to be higher.

In addition, if the detection value indicates a value inside a certainrange, the exposure control section 135, by exposure control subjectedto a disturbance such as a high-luminance subject entering into theobservation range, suppresses sudden changes in exposure in order tosuppress the occurrence of a situation in which the brightness of theimage of the subject changes suddenly.

Specifically, in the case of recognizing that the detection valueindicates a value inside a certain range, the exposure control section135 measures a first interval in which the detection value indicates avalue inside the range, and based on the measurement result of the firstinterval, decides a second interval in which to suppress sudden changesin exposure due to a disturbance. Note that the certain range (that is,the range of the detection value) is decided in advance, based on arange of allowed exposure (in other words, the preferred brightness ofthe image of the subject for observation of the target), using thedetection value corresponding to a correct exposure as a reference, forexample.

Subsequently, even if the detection value changes suddenly due to adisturbance or the like during the decided second interval, the exposurecontrol section 135 controls the operation of the image sensor 113 sothat an exposure corresponding to a detection value inside the certainrange (for example, the correct exposure corresponding to the referencevalue) is maintained. Note that the details of this operation will bediscussed separately later, together with an example of the flow of aseries of processes by the medical observation device.

The above thus references FIG. 3 to describe an example of a functionalconfiguration of a medical observation device according to the presentembodiment, with particular focus on operations related to the controlof the brightness of an image of a subject (in other words, exposurecontrol).

4. Processes

Next, FIG. 4 will be referenced to describe an example of the flow of aseries of processes by the medical observation device according to thepresent embodiment, with particular focus on the operation of exposurecontrol by the medical observation device. FIG. 4 is a flowchartillustrating an example of the flow of a series of processes by themedical observation device according to the present embodiment.

(Step S101)

First, the imaging signal processing section 131 performs detectionprocessing on the electrical signal generated by photoelectricconversion in the image sensor 113, and outputs a result of thedetection process (namely, a detection value) to the exposure controlsection 135.

(Step S105)

If the detection value acquired from the imaging signal processingsection 131 indicates a value inside a certain range, the exposurecontrol section 135 increases an interval over which to maintainexposure (hereinafter designated the “stable time Ts”) even if thedetection value changes suddenly due to a disturbance or the like. Notethat in the present description, the stable time Ts is described asbeing managed based on a counter value that counts one frame as 1. Inother words, in this case, the exposure control section 135 incrementsthe counter value of the stable time Ts.

(Step S107)

In addition, if the acquired detection value indicates a value outsidethe certain range, the exposure control section 135 decrements thecounter value of the stable time Ts. In other words, in this case, thestable time Ts is decreased.

(Steps S109, S111)

Note that an upper limit value on the stable time Ts may also beprovided. In such a case, when the counter value of the stable time Tsis greater than the upper limit value (S109, YES), the exposure controlsection 135 may set the counter value of the stable time Ts to the upperlimit value (S111). Such control thereby deters a situation in which thestable time Ts is increased past the upper limit value. Note that if thecounter value of the stable time Ts is less than or equal to the upperlimit value (S109, NO), the flow proceeds to the next process, withoutexecuting the process indicated by the reference sign S111.

(Steps S113, S115)

In addition, if the counter value of the stable time Ts indicates anegative value (S113, YES), the exposure control section 135 sets thecounter value of the stable time Ts to 0. Such control thereby deters asituation in which the stable time Ts is decreased past 0. Note that ifthe counter value of the stable time Ts is equal to or greater than 0(S113, NO), the flow proceeds to the next process, without executing theprocess indicated by the reference sign S115.

(Steps S117, S119)

In addition, if the counter value of the stable time Ts is greater than0 (S117, YES), the exposure control section 135 treats the detectionvalue inside the certain range discussed above (in other words, thedetection value range) as a target value, and controls the operation ofthe imaging section 110 so that the exposure of the imaging section 110is maintained at an exposure corresponding to the target value. As amore specific example, at this point the exposure control section 135locks the shutter speed of the electronic shutter in the image sensor113 or the gain so that the exposure of the imaging section 110 ismaintained at a correct exposure corresponding to the reference value(S119). Note that if the counter value of the stable time Ts is notgreater than 0 (in other words, in the case of 0) (S117, NO), theexposure control section 135 does not execute the control related tomaintaining exposure indicated by the reference sign S119. In this case,for example, the exposure control section 135 controls the exposure ofthe imaging section 110 according to the acquired detection value sothat the detection value approaches the target value (reference value).

The medical observation device 100 according to the present embodimentsuccessively executes a series of operations as described above at everyinstance of a certain timing, for example. Accordingly, next, an exampleof exposure control based on the series of operations discussed above bya medical observation device according to the present embodiment will bedescribed with reference to FIG. 5. FIG. 5 is an explanatory diagram forexplaining an example of exposure control by a medical observationdevice according to the present embodiment, and illustrates an exampleof the relationship among the detection value, the exposure control, andthe counter value for managing the stable time. In FIG. 5, thehorizontal axis of the graph illustrated on the top and the graphillustrated on the bottom represents time. Also, the vertical axis ofthe graph illustrated on the top represents the detection value. Also,the vertical axis of the graph illustrated on the bottom illustrates thecounter value of the stable time.

In addition, in FIG. 5, the graph indicated by the reference sign g11represents the chronological change in the detection value acquiredbased on the detection process by the imaging signal processing section131. Also, the graph indicated by the reference sign g13 illustrates thechronological change in the exposure based on the control by theexposure control section 135 diagrammatically as the chronologicalchange in the detection value corresponding to the exposure. Also, thegraph indicated by the reference sign g15 represents the chronologicalchange in the counter value of the stable time.

Also, the reference sign R1 indicates the certain range discussedearlier (in other words, the detection value range). Note that in theexample illustrated in FIG. 5, a range of ±TH1 centered on a referencevalue L11 is set as the certain range R1. Herein, the reference signTH1_max indicates a threshold value on the + side of the certain rangeR1 (that is, an upper limit value), while the reference sign TH1_minindicates a threshold value on the − side of the certain range R1 (thatis, a lower limit value). In such a case, when the absolute value of thedifference between the acquired detection value and the reference valueL11 is less than or equal to the threshold value TH1, it is possible torecognize that the detection value indicates a value inside the certainrange R1. Note that the method of setting the certain range R1 (in otherwords, the detection value range) described above is merely one example,and it is not necessarily required to set a range centered on areference value.

In the example illustrated in FIG. 5, as illustrated by the graph g11,the acquired detection value indicates a value inside the certain rangeR1 in the interval from the timings T1 to T3, and indicates a valueoutside the certain range R1 from the timing T3.

At this point, consider the chronological change in the counter value ofthe stable time illustrated as the graph g15. Since the detection valueindicates a value inside the range R1 in the interval from the timingsT1 to T2, the counter value of the stable time increaseschronologically, and reaches an upper limit c_max of the counter valueat the timing T2. Also, in the interval from the timings T2 to T3, thedetection value indicates a value inside the range R1, but the countervalue of the stable time has reached the upper limit c_max, and thus ismaintained so as not to exceed the upper limit c_max. Also, from thetiming T3, the detection value indicates a value outside the range R1,and thus the counter value of the stable time decreases chronologicallyby the amount the counter value increased in the interval from thetimings T1 to T2, and becomes 0 at the timing T4. In other words, in theexample illustrated in FIG. 5, the counter value that increased over thetime Ts of length from the timings T2 to T2 decreases over the stabletime Ts, and reaches 0.

Next, the exposure control of the imaging section 110 by the exposurecontrol section 135 will be described with reference to the graph g13.In the example illustrated in FIG. 5, if the counter value of the stabletime is indicating a value greater than 0, the exposure control section135 treats the reference value L11 (in other words, a detection valueinside the range R1) as a target value, and controls the operation ofthe imaging section 110 so that the exposure of the imaging section 110is maintained at an exposure corresponding to the target value (in otherwords, the correct exposure corresponding to the reference value L11).

More specifically, in the example illustrated in FIG. 5, in the intervalfrom the timings T1 to T4, the counter value of the stable timeindicates a value greater than 0. For this reason, in this interval, theexposure control section 135 controls the operation of the imagingsection 110 so that the exposure of the imaging section 110 ismaintained at the correct exposure corresponding to the reference valueL11.

At this point, consider the interval from the timing T3. As discussedabove, from the timing T3, the detection value rises due to adisturbance, such as a high-luminance subject entering into theobservation range, for example, and the detection value indicates avalue outside the range R1. Meanwhile, in the interval also from thetiming T3 until the timing T4 at which the counter value of the stabletime decreases to reach 0, the exposure control section 135 maintainsthe exposure of the imaging section 110 at the correct exposurecorresponding to the reference value L11, and from the timing T4,switches to exposure control that follows the detection value.

According to such control, even when the detection value changessuddenly due to a disturbance, like a high-luminance subject such asforceps or gauze entering into the observation range, the medicalobservation device 100 maintains the exposure of the imaging section110, and suppresses sudden changes of brightness in the image of thesubject (image of the target of observation). In other words, accordingto the medical observation device 100 according to the presentembodiment, even when a disturbance occurs, like a high-luminance objectsuch as forceps or gauze temporarily entering into the observationrange, it becomes possible to suppress the occurrence of a situation inwhich the captured image of the target of observation becomes dark.

Additionally, even when the detection value indicates a value outsidethe range R1, the interval in which the medical observation device 100maintains the exposure of the imaging section 110 at the correctexposure (second interval) is decided according to the interval in whichthe acquired detection value indicates a value inside the certain rangeR1 (first interval). More specifically, the medical observation device100 performs control so that as the interval in which the detectionvalue indicates a value inside the certain range R1 (first interval)becomes longer, the interval in which the exposure of the imagingsection 110 is maintained at the correct exposure even if the detectionvalue indicates a value outside the range R1 (second interval) alsobecomes longer.

For example, in the example illustrated in FIG. 5, the interval from thetimings T1 to T3 corresponds to the interval in which the detectionvalue indicates a value inside the certain range R1 (first interval).Also, the interval from the timings T1 to T4 corresponds to the intervalin which the exposure of the imaging section 110 is maintained at thecorrect exposure (second interval). In other words, the medicalobservation device 100 according to the present embodiment dynamicallycontrols the interval in which the exposure of the imaging section 110is maintained at the correct exposure, according to changes ofbrightness in the observation range. For this reason, according to themedical observation device 100 according to the present embodiment, itbecomes possible to achieve, with a more favorable mode, both thesuppression of sudden changes of brightness in the image of the subjectas discussed above, and the tracking of the brightness of the image withrespect to changes of brightness in the observation range.

The foregoing thus references FIGS. 4 and 5 to describe an example ofthe flow of a series of processes by the medical observation deviceaccording to the present embodiment, with particular focus on theoperation of exposure control by the medical observation device.

5. Modifications

Next, as a modification of the medical observation device according tothe present embodiment, another example of exposure control by themedical observation device will be described. As discussed above, themedical observation device according to the present embodimentcalculates a second interval in which to suppress sudden changes inexposure due to a disturbance, based on a first interval in which thedetection value indicates a value inside the certain range R1. On theother hand, the mode of such control is not particularly limited,insofar as the medical observation device is able to maintain theexposure of the imaging section 110 at an exposure based on a detectionvalue inside the range R1 in the second interval.

For example, in the example discussed above with reference to FIG. 5,the medical observation device 100 starts the control of the imagingsection 110 so that the exposure of the imaging section 110 reaches thecorrect exposure, while using the timing T1 at which the acquireddetection value indicates a value inside the certain range R1 as a basepoint. On the other hand, insofar as the exposure of the imaging section110 is maintained at an exposure based on a detection value inside thecertain range R1 in the interval from the timings T1 to T4, the timingat which the medical observation device 100 starts the control of theoperation of the imaging section 110 is not necessarily limited to thetiming T1 in FIG. 5.

For example, FIG. 6 is an explanatory diagram for explaining an exampleof exposure control by a medical observation device according to amodification of the present embodiment. Also, the vertical axis and thehorizontal axis in each of the graphs respectively illustrated on thetop and the bottom of FIG. 6 correspond to the vertical axis and thehorizontal axis of the graphs respectively illustrated on the top andthe bottom of FIG. 5. Note that in the example illustrated in FIG. 6,the graphs indicated by the reference signs g11 and g15 are similar tothe graphs g11 and g15 in the example illustrated in FIG. 5, and thusdetailed description will be reduced or omitted. Also, the graphindicated by the reference sign g23 corresponds to the graph g13 in FIG.5, and illustrates the chronological change in the exposure based on thecontrol by the medical observation device 100 diagrammatically as thechronological change in the detection value corresponding to theexposure.

The example illustrated in FIG. 6 is similar to the example illustratedin FIG. 5, in that the medical observation device 100 starts measuringthe counter value of the stable time at the timing T1. On the otherhand, as a consideration of the graph g23 demonstrates, the exampleillustrated in FIG. 6 differs from the example illustrated in FIG. 5, inthat the medical observation device 100 does not conduct the exposurecontrol of the imaging section 110 in the interval in which thedetection value indicates a value inside the certain range R1, and laterstarts the exposure control of the imaging section 110 using the timingT3 at which the detection value indicates a value outside the range R1as a base point.

Note that for the interval from the timing T3, similarly to the exampleillustrated in FIG. 5, the medical observation device 100 maintains theexposure of the imaging section 110 at the correct exposurecorresponding to the reference value L11 in the interval up to thetiming T4 at which the counter value of the stable time decreases toreach 0. Additionally, from the timing T4, the medical observationdevice 100 switches the exposure control of the imaging section 110 tocontrol that follows the detection value. According to such control, inthe example illustrated in FIG. 6, in a second interval in which tosuppress sudden changes in exposure due to a disturbance (the intervalindicated from the timings T1 to T4), the medical observation device 100maintains the exposure of the imaging section 110 at an exposure basedon a detection value inside the certain range R1.

Also, as another example, in the examples illustrated in FIGS. 5 and 6,the medical observation device 100 treats the reference value L11 as atarget value to control the operation of the imaging section 110 so thatthe exposure of the imaging section 110 is maintained at an exposurecorresponding to the target value. On the other hand, the target valuefor controlling the exposure of the imaging section 110 is notnecessarily limited to a certain reference value L11.

For example, FIG. 7 is an explanatory diagram for explaining anotherexample of exposure control by a medical observation device according toa modification of the present embodiment. Also, the vertical axis andthe horizontal axis in each of the graphs respectively illustrated onthe top and the bottom of FIG. 7 correspond to the vertical axis and thehorizontal axis of the graphs respectively illustrated on the top andthe bottom of FIG. 6, for example. Note that in the example illustratedin FIG. 7, the graphs indicated by the reference signs g11 and g15 aresimilar to the graphs g11 and g15 in the example illustrated in FIG. 6,and thus detailed description will be reduced or omitted. Also, thegraph indicated by the reference sign g33 corresponds to the graph g23in FIG. 6, and illustrates the chronological change in the exposurebased on the control by the medical observation device 100diagrammatically as the chronological change in the detection valuecorresponding to the exposure.

In the example illustrated in FIG. 7, as indicated by the graph g15, theoperation related to the measurement of the counter value of the stabletime by the medical observation device 100 is similar to the examplesillustrated in FIGS. 5 and 6. On the other hand, the example illustratedin FIG. 7 differs from the examples illustrated in FIGS. 5 and 6 inthat, as indicated by the graph g33, the medical observation device 100sets a target value L12 different from the reference value L11 as thetarget value of the exposure control.

As a specific example, the medical observation device 100 calculates thetarget value L12 based on statistics of the detection value in aninterval in which the acquired detection value indicates a value insidethe range R1 (such as an average of the detection value from the timingsT1 to T2, or a moving average of the detection value based on a certaintime step, for example). Subsequently, from the timing T3 at which theacquired detection value indicates a value outside the range R1, themedical observation device 100 controls the operation of the imagingsection 110 so that the exposure of the imaging section 110 ismaintained at the exposure corresponding to the calculated target valueL12. According to such control, in the example illustrated in FIG. 7, ina second interval in which to suppress sudden changes in exposure due toa disturbance (the interval indicated from the timings T1 to T4), themedical observation device 100 maintains the exposure of the imagingsection 110 at an exposure based on a detection value inside the certainrange R1.

Next, another example of exposure control by a medical observationdevice according to a modification of the present embodiment will bedescribed with reference to FIG. 8. The vertical axis and the horizontalaxis in each of the graphs respectively illustrated on the top and thebottom of FIG. 8 correspond to the vertical axis and the horizontal axisof the graphs respectively illustrated on the top and the bottom of FIG.6, for example. In addition, in FIG. 8, the graph indicated by thereference sign g41 represents the chronological change in the detectionvalue acquired based on the detection process by the medical observationdevice 100 (imaging signal processing section 131). Also, the graphindicated by the reference sign g43 illustrates the chronological changein the exposure based on the control by the medical observation device100 (exposure control section 135) diagrammatically as the chronologicalchange in the detection value corresponding to the exposure. Also, thegraph indicated by the reference sign g45 represents the chronologicalchange in the counter value of the stable time. Also, the rangeindicated by the reference sign R1 is similar to the examples describedwith reference to FIGS. 5 to 7.

In the example illustrated in FIG. 8, as illustrated by the graph g41,the acquired detection value indicates a value inside the range R1 inthe interval from the timings T21 to T23, and subsequently, temporarilyindicates a value outside the range R1 due to a disturbance or the likein the interval from the timings T23 to T24. Also, the acquireddetection value indicates a value inside the range R1 in the intervalfrom the timings T24 to T26, and indicates a value outside the range R1from the timing T26.

At this point, consider the chronological change in the counter value ofthe stable time illustrated as the graph g45. Since the detection valueindicates a value inside the range R1 in the interval from the timingsT21 to T22, the counter value of the stable time increaseschronologically, and reaches the upper limit c_max at the timing T22.Also, in the interval from the timings T22 to T23, the detection valueindicates a value inside the range R1, but the counter value of thestable time has reached the upper limit c_max, and thus is maintained soas not to exceed the upper limit c_max.

Also, in the interval from the timings T23 to T24, since the detectionvalue indicates a value outside the range R1, the counter value of thestable time decreases chronologically. Note that in the exampleillustrated in FIG. 8, at the timing T24, the detection value indicatesa value inside the range R1 again, before the counter value of thestable time reaches 0. For this reason, in the interval from the timingsT24 to T25, the counter value of the stable time increaseschronologically again, and reaches the upper limit c_max at the timingT25. Also, in the interval from the timings T25 to T26, the detectionvalue indicates a value inside the range R1, but the counter value ofthe stable time has reached the upper limit c_max, and thus ismaintained so as not to exceed the upper limit c_max.

Also, from the timing T26, the detection value indicates a value outsidethe range R1, and thus the counter value of the stable time decreaseschronologically by the amount the counter value increased up to thetiming T26, and reaches 0 at the timing T27.

Next, the exposure control of the imaging section 110 by the medicalobservation device 100 (exposure control section 135) will be describedwith reference to the graph g43. In the example illustrated in FIG. 8,if the acquired detection value indicates a value outside the range R1,and in addition, the counter value of the stable time indicates a valuegreater than 0, the medical observation device 100 controls theoperation of the imaging section 110 so that the exposure of the imagingsection 110 is maintained at the exposure corresponding to the referencevalue L11.

For example, in the example illustrated in FIG. 8, in the interval fromthe timings T23 to T24, the acquired detection value indicates a valueoutside the range R1, and in addition, the counter value of the stabletime indicates a value greater than 0. For this reason, in thisinterval, the medical observation device 100 controls the operation ofthe imaging section 110 so that the exposure of the imaging section 110is maintained at the exposure corresponding to the reference value L11.

Next, consider the interval from the timings T24 to T26. At the timingT24, the acquired detection value indicates a value inside the range R1again. For this reason, the medical observation device 100 switches theoperation of the imaging section 110 so that the exposure of the imagingsection 110 follows the acquired detection value.

Also, in the interval from the timing T26, the acquired detection valueindicates a value outside the range R1. Additionally, the counter valueof the stable time decreases chronologically from the timing T26, andreaches 0 at the timing T27. In other words, in the interval from thetimings T26 to T27, the medical observation device 100 controls theoperation of the imaging section 110 so that the exposure of the imagingsection 110 is maintained at the exposure corresponding to the referencevalue L11. Subsequently, from the timing T27, the medical observationdevice 100 switches the operation of the imaging section 110 so that theexposure of the imaging section 110 follows the acquired detectionvalue.

Note that in the example illustrated in FIG. 8, the interval from thetimings T21 to T23 and the interval from the timings T24 to T26, inwhich the acquired detection value indicates a value inside the rangeR1, correspond to the first interval. Meanwhile, the interval from thetimings T21 to T27 corresponds to the second interval in which tosuppress sudden changes in exposure due to a disturbance.

As above, in the example illustrated in FIG. 8, if the acquireddetection value indicates a value outside the range R1, and in addition,the counter value of the stable time indicates a value greater than 0,the medical observation device 100 controls the operation of the imagingsection 110 so that the exposure of the imaging section 110 ismaintained at the exposure corresponding to the reference value L11.According to such control, in the example illustrated in FIG. 8, in theinterval in which the acquired detection value indicates a value outsidethe range R1, which takes place during the decided second interval, themedical observation device 100 becomes able to control the operation ofthe imaging section 110 so that the exposure of the imaging section 110is maintained at the exposure corresponding to the reference value L11.

Note that the exposure control by the medical observation device 100described above is merely one example, and the mode of such control isnot particularly limited, insofar as the medical observation device isable to maintain the exposure of the imaging section 110 at an exposurebased on a detection value inside the certain range R1 in the calculatedsecond interval. For example, in the example illustrated in FIG. 8, inthe interval from the timings T21 to T27, the medical observation device10 may control the operation of the imaging section 110 so that theexposure of the imaging section 110 is maintained at the exposurecorresponding to the reference value L11, similarly to the exampledescribed with reference to FIG. 5. Also, as another example, themedical observation device 100 may start the exposure control of theimaging section 110 at the timing T23, and maintain the exposure controluntil the timing T27. In other words, in the interval from the timingsT23 to T27, the medical observation device 100 may control the operationof the imaging section 110 so that the exposure of the imaging section110 is maintained at the exposure corresponding to the reference valueL11. Also, in the example illustrated in FIG. 8, the medical observationdevice 100 may also separately calculate a target value L12 differentfrom the reference value L11, and control the exposure of the imagingsection 110 based on the target value L12, similarly to the exampleillustrated in FIG. 7.

The above thus describes, as a modification of the medical observationdevice according to the present embodiment, other examples of exposurecontrol by the medical observation device with reference to FIGS. 6 to8.

6. Applications

Next, FIG. 9 will be referenced to describe an example of a case ofusing a surgical video microscope device equipped with an arm as anotherapplication of a medical observation device according to the presentembodiment. FIG. 9 is an explanatory diagram for explaining anapplication of a medical observation device according to the embodiment.

FIG. 9 diagrammatically illustrates how a medical procedure is performedusing a surgical video microscope device. Specifically, referring toFIG. 9, a state is illustrated in which a physician acting as thesurgeon (user) 520 is using a surgical tool 521, such as a scalpel,tweezers, or forceps, for example, to perform surgery on a subject(patient) 540 lying on an operating table 530. Note that in thefollowing description, medical procedure is used as a collective term todenote various types of medical treatments performed by a physicianacting as the user 520 on a patient acting as the subject 540, such as asurgery or an examination. Also, although the example illustrated inFIG. 9 illustrates a situation of surgery as an example of a medicalprocedure, the medical procedure in which the surgical video microscopedevice 510 is used is not limited to surgery, and may be any of variousother types of medical procedures.

Beside the operating table 530, the surgical video microscope device 510according to the present embodiment is provided. The surgical videomicroscope device 510 is equipped with a base section 511 which acts asa base, an arm section 512 which extends from the base section 511, andan imaging unit 515 connected as a front edge unit on the front edge ofthe arm section 512. The arm section 512 includes multiple jointsections 513 a, 513 b, and 513 c, multiple links 514 a and 514 b joinedby the joint sections 513 a and 513 b, and the imaging unit 515 providedon the front edge of the arm section 512. In the example illustrated inFIG. 9, for the sake of simplicity, the arm section 512 includes threejoint sections 513 a to 513 c and two links 514 a and 514 b, but inactuality, the degrees of freedom in the positions and the orientationsof the arm section 512 and the imaging unit 515 may be considered toappropriately configure factors such as the numbers and shapes of thejoint sections 513 a to 513 c and the links 514 a and 514 b, and thedirections of the drive shafts of the joints 513 a to 513 c, so as toachieve the desired degrees of freedom.

The joint sections 513 a to 513 c have a function of rotatably joiningthe links 514 a and 514 b to each other, and by driving the rotation ofthe joint sections 513 a to 513 c, the driving of the arm section 512 iscontrolled.

On the front edge of the arm section 512, the imaging unit 515 isconnected as a front edge unit. The imaging unit 515 is a unit thatacquires an image of an imaging target, and is a device such as a cameracapable of capturing a moving image or a still image, for example. Asillustrated in FIG. 9, the orientations and the positions of the armsection 512 and the imaging unit 515 are controlled by the surgicalvideo microscope device 510 so that the imaging unit 515 provided on thefront edge of the arm section 512 captures the operating site of thesubject 540. Note that the configuration of the imaging unit 515connected as the front edge unit on the front edge of the arm section512 is not particularly limited, and the imaging unit 515 may beconfigured as an endoscope or a microscope, for example. Additionally,the imaging unit 515 may also be configured to be removable from the armsection 512. According to such a configuration, an imaging unit 515depending on the usage scenario may be connected appropriately to thefront edge of the arm section 512 as the front edge unit, for example.Note that although the description herein focuses on a case in which theimaging unit 515 is applied as the front edge unit, obviously the frontedge unit connected to the front edge of the arm section 512 is notnecessarily limited to the imaging unit 515.

Also, at a position facing the user 520, a display device 550 such as amonitor or a display is installed. An image of the operating siteacquired by the imaging unit 515 is subjected to various types of imageprocessing by an image processing device built into or externallyattached to the surgical video microscope device 510, and then displayedon a display screen of the display device 550 as an electronic image.According to such a configuration, the user 520 becomes able to performvarious treatments (such as surgery, for example) while looking at anelectronic image of the operating site displayed on the display screenof the display device 550.

Note that in the example illustrated in FIG. 9, the imaging unit 515includes the imaging section 110 discussed earlier with reference toFIG. 3, for example. Also, the imaging processing device that performsvarious types of image processing on an image of the operating siteacquired by the imaging unit 515 corresponds to an example of thecontrol section 130 discussed earlier with reference to FIG. 3.Similarly, the display device 550 corresponds to an example of thedisplay section 150 discussed earlier with reference to FIG. 3.

The above thus references FIG. 9 to describe an example of a case ofusing a surgical video microscope device equipped with an arm as anotherapplication of a medical observation device according to the presentembodiment.

7. Hardware Configuration

Next, an example of a hardware configuration of an informationprocessing apparatus 900 configured as a medical observation deviceaccording to the present embodiment will be described in detail withreference to FIG. 10. FIG. 10 is a function block diagram illustratingan example configuration of the hardware configuration of an informationprocessing apparatus 900 configured as a medical observation deviceaccording to an embodiment of the present disclosure.

As illustrated in FIG. 10, the information processing apparatus 900mainly includes a CPU 901, a ROM 903, and a RAM 905. Furthermore, theinformation processing apparatus 900 also includes a host bus 907, abridge 909, an external bus 911, an interface 913, an input apparatus915, an output apparatus 917, and a storage apparatus 919. Furthermore,the information processing apparatus 900 also includes a drive 921, aconnection port 923, and a communication apparatus 925.

The CPU 901 serves as an arithmetic processing apparatus and a controlapparatus, and controls the overall operation or a part of the operationof the information processing apparatus 900 according to variousprograms recorded in the ROM 903, the RAM 905, the storage apparatus919, or a removable recording medium 927. The ROM 903 stores programs,operation parameters, and the like used by the CPU 901. The RAM 905primarily stores programs that the CPU 901 uses and parameters and thelike varying as appropriate during the execution of the programs. Theseare connected with each other via the host bus 907 configured from aninternal bus such as a CPU bus or the like. Note that the respectivecomponents of the control section 130 discussed earlier with referenceto FIG. 3 may be realized by the CPU 901, for example.

The host bus 907 is connected to the external bus 911 such as a PCI(Peripheral Component Interconnect/Interface) bus via the bridge 909.Additionally, the input apparatus 915, the output apparatus 917, thestorage apparatus 919, the drive 921, the connection port 923, and thecommunication apparatus 925 are connected to the external bus 911 viathe interface 913.

The input apparatus 915 is an operation mechanism operated by a user,such as a mouse, a keyboard, a touch panel, buttons, a switch, a lever,or a pedal. Also, the input apparatus 915 may be a remote controlmechanism (a so-called remote control) using, for example, infraredlight or other radio waves, or may be an externally connected apparatus929 such as a mobile phone or a PDA conforming to the operation of theinformation processing apparatus 900. Furthermore, the input apparatus915 generates an input signal based on, for example, information whichis input by a user with the above operation mechanism, and is configuredfrom an input control circuit for outputting the input signal to the CPU901. The user of the information processing apparatus 900 can inputvarious data to the information processing apparatus 900 and caninstruct the information processing apparatus 900 to perform processingby operating this input apparatus 915.

The output apparatus 917 is configured from a device capable of visuallyor audibly notifying acquired information to a user. Examples of suchdevice include display apparatuses such as a CRT display apparatus, aliquid crystal display apparatus, a plasma display apparatus, an ELdisplay apparatus and lamps, audio output apparatuses such as a speakerand a headphone, a printer, and the like. For example, the outputapparatus 917 outputs a result obtained by various processings performedby the information processing apparatus 900. More specifically, thedisplay apparatus displays, in the form of texts or images, a resultobtained by various processes performed by the information processingapparatus 900. On the other hand, the audio output apparatus converts anaudio signal such as reproduced audio data and sound data into an analogsignal, and outputs the analog signal. Note that the display section 150discussed earlier with reference to FIG. 3 may be realized by the outputapparatus 917, for example.

The storage apparatus 919 is a device for storing data configured as anexample of a storage unit of the information processing apparatus 900and is used to store data. The storage apparatus 919 is configured from,for example, a magnetic storage apparatus such as a HDD (Hard DiskDrive), a semiconductor storage apparatus, an optical storage apparatus,or a magneto-optical storage apparatus. This storage apparatus 919stores programs to be executed by the CPU 901, and various data.

The drive 921 is a reader/writer for recording medium, and is embeddedin the information processing apparatus 900 or attached externallythereto. The drive 921 reads information recorded in the attachedremovable recording medium 927 such as a magnetic disk, an optical disk,a magneto-optical disk, or a semiconductor memory, and outputs the readinformation to the RAM 905. Furthermore, the drive 921 can write in theattached removable recording medium 927 such as a magnetic disk, anoptical disk, a magneto-optical disk, or a semiconductor memory. Theremovable recording medium 927 is, for example, a DVD medium, an HD-DVDmedium, or a Blu-ray (a registered trademark) medium. The removablerecording medium 927 may be a CompactFlash (CF; a registered trademark),a flash memory, an SD memory card (Secure Digital Memory Card), or thelike. Alternatively, the removable recording medium 927 may be, forexample, an IC card (Integrated Circuit Card) equipped with anon-contact IC chip or an electronic appliance.

The connection port 923 is a port for allowing apparatuses to directlyconnect to the information processing apparatus 900. Examples of theconnection port 923 include a USB (Universal Serial Bus) port, anIEEE1394 port, a SCSI (Small Computer System Interface) port, and thelike. Other examples of the connection port 923 include an RS-232C port,an optical audio terminal, an HDMI (a registered trademark)(High-Definition Multimedia Interface) port, and the like. By theexternally connected apparatus 929 connecting to this connection port923, the information processing apparatus 900 directly obtains variousdata from the externally connected apparatus 929 and provides variousdata to the externally connected apparatus 929.

The communication apparatus 925 is a communication interface configuredfrom, for example, a communication apparatus for connecting to acommunication network 931. The communication apparatus 925 is, forexample, a wired or wireless LAN (Local Area Network), Bluetooth(registered trademark), a communication card for WUSB (Wireless USB), orthe like. Alternatively, the communication apparatus 925 may be a routerfor optical communication, a router for ADSL (Asymmetric DigitalSubscriber Line), a modem for various communications, or the like. Thiscommunication apparatus 925 can transmit and receive signals and thelike in accordance with a predetermined protocol such as TCP/IP on theInternet and with other communication apparatuses, for example. Thecommunication network 931 connected to the communication apparatus 925is configured from a network and the like, which is connected via wireor wirelessly, and may be, for example, the Internet, a home LAN,infrared communication, radio wave communication, satellitecommunication, or the like.

Heretofore, an example of the hardware configuration capable ofrealizing the functions of the information processing apparatus 900constituting a medical stereoscopic observation system according to theembodiment of the present disclosure has been shown. Each of thestructural elements described above may be configured using ageneral-purpose material, or may be configured from hardware dedicatedto the function of each structural element. Accordingly, the hardwareconfiguration to be used can be changed as appropriate according to thetechnical level at the time of carrying out the present embodiment.Although not shown in FIG. 10, for example, it naturally includesvarious configurations corresponding to the medical stereoscopicobservation device described above.

Note that it is also possible to develop a computer program forrealizing the respective functions of the information processingapparatus 900 constituting a medical stereoscopic observation systemaccording to the present embodiment as discussed above, and implementthe computer program in a personal computer or the like. In addition, acomputer-readable recording medium storing such a computer program mayalso be provided. The recording medium may be a magnetic disc, anoptical disc, a magneto-optical disc, or flash memory, for example.Furthermore, the above computer program may also be delivered via anetwork, for example, without using a recording medium.

8. Conclusion

Thus, as described above, a medical observation device according to thepresent embodiment, in the case of recognizing that the detection valueindicates a value within a certain range, measures a first interval inwhich the detection value indicates a value inside the range, and basedon the measurement result of the first interval, decides a secondinterval in which to suppress sudden changes in exposure due to adisturbance. Subsequently, even if the detection value changes suddenlydue to a disturbance or the like during the decided second interval, themedical observation device controls the operation of the imaging sectionso that the exposure of the imaging section is maintained at an exposurecorresponding to a detection value within the certain range (forexample, the correct exposure corresponding to the reference value).

According to such control, even when the detection value changessuddenly due to a disturbance, like a high-luminance subject such asforceps or gauze entering into the observation range, the medicalobservation device according to the present embodiment maintains theexposure of the imaging section, and suppresses sudden changes ofbrightness in the image of the subject (image of the target ofobservation), such as an affected area. In other words, according to themedical observation device according to the present embodiment, even ifa high-luminance object such as forceps or gauze temporarily enters intothe observation range, it becomes possible to suppress the occurrence ofa situation in which the captured image of the target of observationbecomes dark.

Also, as discussed earlier, the second interval in which a medicalobservation device according to the present embodiment suppresses suddenchanges in exposure due to a disturbance is decided based on the firstinterval in which the detection value indicates a value inside thecertain range. Namely, the medical observation device controls thesecond interval to be longer as the first interval becomes longer. Inother words, the medical observation device according to the presentembodiment dynamically controls the interval in which the exposure ofthe imaging section is maintained at an exposure corresponding to adetection value inside the certain range (for example, the correctexposure), according to changes of brightness in the observation range.For this reason, according to the medical observation device accordingto the present embodiment, it becomes possible to achieve, with a morefavorable mode, both the suppression of sudden changes of brightness inthe image of the subject as discussed above, and the tracking of thebrightness of the image with respect to changes of brightness in theobservation range.

The preferred embodiment(s) of the present disclosure has/have beendescribed above with reference to the accompanying drawings, whilst thepresent disclosure is not limited to the above examples. A personskilled in the art may find various alterations and modifications withinthe scope of the appended claims, and it should be understood that theywill naturally come under the technical scope of the present disclosure.

Further, the effects described in this specification are merelyillustrative or exemplified effects, and are not limitative. That is,with or in the place of the above effects, the technology according tothe present disclosure may achieve other effects that are clear to thoseskilled in the art based on the description of this specification.

Additionally, the present technology may also be configured as below.

(1)

A medical observation device, including:

an acquisition section that acquires a sensing result of a brightness ofan image of a subject in a living organism; and

a control section that decides, according to a first interval in whichthe brightness sensing result indicates a value inside a certain range,a second interval in which to maintain an exposure of an imaging sectionat an exposure corresponding to a value included in the range.

(2)

The medical observation device according to (1), wherein

the control section decides, according to the first interval using as abase point a timing at which the value inside the range is sensed as thesensing result, the second interval using the timing as a base point.

(3)

The medical observation device according to (2), wherein

the control section starts control of the exposure of the imagingsection, using the timing as a base point.

(4)

The medical observation device according to (2), wherein

the control section starts control of the exposure of the imagingsection, using another timing later than the timing during the secondinterval as a base point.

(5)

The medical observation device according to (4), wherein

the other timing is a timing at which a value outside the range issensed as the sensing result.

(6)

The medical observation device according to (2), wherein

the control section controls the exposure of the imaging section in aninterval in which the sensing result indicates a value outside the rangeduring the second interval.

(7)

The medical observation device according to any one of (1) to (6),wherein

the control section controls the imaging section so that the exposure ofthe imaging section is maintained at an exposure corresponding to acertain target value included in the range.

(8)

The medical observation device according to any one of (1) to (6),wherein

the control section calculates a target value for controlling theexposure of the imaging section based on the sensing result.

(9)

The medical observation device according to any one of (1) to (8),wherein

the control section sets an increase of the second interval according tothe first interval, in a range that does not exceed a certain thresholdvalue.

(10)

The medical observation device according to any one of (1) to (9),further including:

the imaging section.

(11)

The medical observation device according to (10), wherein

the imaging section is an endoscope configured to be inserted into abody cavity of a patient.

(12)

The medical observation device according to (10), wherein

the imaging section is a microscope section including an optical systemthat acquires an optical image of the subject, and

the medical observation device further includes a support section thatsupports the microscope section.

(13)

A medical observation method, executed by a processor, including:

acquiring a sensing result of a brightness of an image of a subject in aliving organism; and

deciding, according to a first interval in which the brightness sensingresult indicates a value inside a certain range, a second interval inwhich to maintain an exposure of an imaging section at an exposurecorresponding to a value included in the range.

REFERENCE SIGNS LIST

-   1 endoscopic surgical system-   11 camera head-   11 endoscope-   13 CCU-   15 display device-   17 light source device-   21 treatment tool device-   22 energy treatment tool-   23 forceps-   24 pneumoperitoneum device-   25 a, 25 b trocar-   26 recorder-   27 printer-   31 cart-   33 patient bed-   35 footswitch-   100 medical observation device-   110 imaging section-   111 imaging optical system-   113 image sensor-   130 control section-   131 imaging signal processing section-   133 image processing section-   135 exposure control section-   150 display section

1: A surgical imaging system, comprising: a surgical imaging deviceconfigured to capture an image of a surgical site by radiating lightonto the surgical site; and processing circuitry configured to acquire asensing result of a brightness of the image of the surgical site duringa first time interval, control, during the first time interval, anexposure of an imaging by the surgical imaging device based on thesensing result of the brightness of the image of the surgical siteacquired during the first time interval, and control, during a secondtime interval after the first time interval, a maintaining of anexposure of an imaging by the surgical imaging device, at an exposurecorresponding to a value included in a predetermined range, based oninformation other than a sensing result of a brightness of the image ofthe surgical site acquired during the second time interval. 2: Thesurgical imaging system according to claim 1, wherein a captured imagecaptured by the surgical imaging device during the second time intervalincludes a surgical instrument or forceps or gauze. 3: The surgicalimaging system according to claim 1, wherein the information other thanthe sensing result of the brightness of the image of the surgical siteduring the second time interval is information corresponding to thefirst interval in which the brightness sensing result indicates thevalue inside the predetermined range. 4: The surgical imaging systemaccording to claim 1, wherein the processing circuitry is configured tomaintain a shutter speed of the surgical imaging device to maintain theexposure of the imaging during the second time interval. 5: The surgicalimaging system according to claim 1, wherein the processing circuitry isconfigured to maintain a gain of the surgical imaging device to maintainthe exposure of the imaging during the second time interval. 6: Thesurgical imaging system according to claim 1, wherein the processingcircuitry is configured to maintain an exposure of the imaging by thesurgical imaging device during the first time interval. 7: The surgicalimaging system according to claim 6, wherein the processing circuitry isconfigured to maintain a shutter speed of the surgical imaging device tomaintain the exposure of the imaging during the first time interval. 8:The surgical imaging system according to claim 6, wherein the processingcircuitry is configured to maintain a gain of the surgical imagingdevice to maintain the exposure of the imaging during the first timeinterval. 9: The surgical imaging system according to claim 6, whereinthe processing circuitry is configured to control the exposure of theimaging by the surgical imaging device so that the exposure of theimaging during the second time interval is equal to the exposure of theimaging during the first time interval. 10: The surgical imaging systemaccording to claim 1, wherein the processing circuitry is configured todecide, according to the first time interval using, as a base point, atiming at which the value inside the predetermined range is sensed asthe sensing result, the second time interval using the timing as thebase point. 11: The surgical imaging system according to claim 10,wherein the processing circuitry is configured to start control of theexposure of the imaging section, using the timing as the base point. 12:The surgical imaging system according to claim 10, wherein theprocessing circuitry is configured to start control of the exposure ofthe imaging section, using another timing later than the timing, duringthe second time interval as the base point. 13: The surgical imagingsystem according to claim 12, wherein the other timing is a timing atwhich a value outside the range is sensed as the sensing result. 14: Thesurgical imaging system according to claim 10, wherein the processingcircuitry is configured to control the exposure of the imaging sectionin a time interval in which the sensing result indicates a value outsidethe range during the second time interval. 15: The surgical imagingsystem according to claim 1, wherein the processing circuitry isconfigured to control the imaging section so that the exposure of theimaging section is maintained at an exposure corresponding to a certaintarget value included in the predetermined range. 16: The surgicalimaging system according to claim 1, wherein the processing circuitry isconfigured to calculate a target value for controlling the exposure ofthe imaging section based on the sensing result. 17: The surgicalimaging system according to claim 1, wherein the processing circuitry isconfigured to set an increase of the second time interval according tothe first time interval, in a range that does not exceed a certainthreshold value. 18: The surgical imaging system according to claim 1,wherein the surgical imaging device comprises an endoscope configured tobe inserted into a body cavity of a patient. 19: The surgical imagingsystem according to claim 1, wherein the surgical imaging devicecomprises a microscope including an optical system that acquires anoptical image of the subject. 20: The surgical imaging system accordingto claim 18, further comprises an arm that supports the microscope. 21:A surgical imaging method, comprising: capturing, using a surgicalimaging device, an image of a surgical site by radiating light onto thesurgical site; acquiring, using processing circuitry, a sensing resultof a brightness of the image of the surgical site during a first timeinterval; controlling, during the first time interval, an exposure of animaging by the surgical imaging device based on the sensing result ofthe brightness of the image of the surgical site acquired during thefirst time interval; and controlling, using the processing circuitry andduring a second time interval after the first time interval, amaintaining of the exposure of the imaging by the surgical imagingdevice at an exposure level corresponding to a value included in apredetermined range based on information other than a sensing result ofa brightness of the image of the surgical site acquired during thesecond time interval. 22: A surgical imaging control device, comprising:processing circuitry configured to acquire a sensing result of abrightness of an image of a surgical site during a first time interval,control, during the first time interval, an exposure of an imaging by asurgical imaging device based on the sensing result of the brightness ofthe image of the surgical site acquired during the first time interval,and control, during a second time interval after the first timeinterval, a maintaining of the exposure of the imaging by the surgicalimaging device configured to capture the image of the surgical site byradiating light onto the surgical site, at an exposure levelcorresponding to a value included in a predetermined range based oninformation other than a sensing result of a brightness of the image ofthe surgical site acquired during the second time interval.